There are a wide range of things that impact costs within a global mobility program. The generousness of the policy, the number of exceptions made to the policy in supporting employee mobility, the costs of the supply chain, and the cost of living in the departure and destination locations of the relocating employee are all examples.

While there are others, let's just consider the impact of the cost of living. The Economist Intelligence Unit conducts "The Worldwide Cost of Living Survey" twice annually. This survey compares more than 400 individual prices across 160 products and services. Categories include food, drink, clothing, household supplies and personal care items, home rents, transport, utility bills, private schools, domestic help and recreational costs.

Keeping knowledgeable on global cost of living can help you understand how your mobility volumes in and out of specific places might impact the costs within your global mobility program. Moving more people from less expensive to more expensive locations is likely to increase allowances paid out for housing, schools, transportation and overall cost of living.

So, what are the most expensive (and least expensive) locations...drum roll? The most expensive location is Singapore, which has been at the top of this list for four consecutive years. The least expensive location is Almaty in Kazakhstan.

Then there are a few to note that have had costs jump most significantly in the rankings. Those being: Sao Paulo, Rio de Janeiro, Wellington, Auckland, Brisbane and Adelaide. According to the report, "Five years ago São Paulo was among the 30 most expensive cities in the world but last year it was among the 30 cheapest cities. Over the past year, a recovery in the value of the Real (Brazil’s currency) and almost double-digit inflation have pushed São Paulo and Rio de Janeiro up to 78th and 86th place respectively."